Abstract: A multi-layer class identifying communication apparatus, includes an input interface connected to input communication lines; a switch circuit; and an output interface connected to output communication lines. The input interface comprises an allocating section which determines a class identifier indicative of one of classes to which an IP packet belongs, from header data of the IP packet received through one of the input communication lines, and allocates an IP-QOS (Internet-Protocol-Quality-of-Service) code to the IP packet. The switch circuit selects one of the output communication lines based on a destination address of the IP packet, such that the IP packet is outputted from the output interface to the selected output communication output interface.

Abstract: A network node of a SONET ring is provided with a tributary line interface that receives packets from LAN users. A packet switch performs a switching operation on the LAN packets. An aggregate line interface establishes an STM path on a communication link and a number of packet paths within the STM path. An STM switch connects the packet switch between the tributary line interface and the aggregate line interface so that the switched packets are transported over the packet paths. Monitoring circuitry monitors the LAN packets and produces a warning signal if an abnormal condition is detected in one of the packet paths and transmits the warning signal to the communication link. Preferably, the monitoring circuitry is provided in the tributary line interface.

Abstract: An optical network with an optical adaptation layer whose order is higher than synchronous optical network (SONET) layer and lower than Internet protocol (IP) layer is provided. The optical adaptation layer is configured to construct an optical adaptation frame into which IP flows are aggregated at an edge node.

Abstract: A spiral coil shaped insertion body is composed of a cylinder portion having a fixed outside diameter and a taper portion having an outside diameter gradually reduced from the cylinder portion toward its distal end. The outside thread pitch diameter of the cylinder portion is greater than the pitch diameter of the female screw, and the inside thread pitch diameter of a region of the taper portion covering one or more turns is smaller than the pitch diameter of a male screw. The distal end of the taper portion may be extended directly to form a small-diameter cylinder portion.

Abstract: A client line accommodation unit for accommodating a variety of transmission data on a client-by-client basis comprises a path switch for performing a switching operation. A plurality of the client line accommodation units are interconnected in a mesh configuration through the path switches included therein to realize a small-scale path crossing connect device. On the other hand, a plurality of the client line accommodation units may be interconnected in a fixed manner through the path switches included therein to realize a service multiplexer device. In addition, a large-scale path switch may be added for expanding the switching capacity to realize a large-scale path crossing connect device.

Abstract: A female screw mechanism and a nut, comprising an insert attached to a female screw. The diameter of at least one turn at one end of the insert on the side for the insertion of a male screw into the insert is smaller than the diameter of the male screw. The other end of the insert is fixed to a female screw component, such as the nut, by welding, adhesive bonding, etc. A bent portion on the other end of the insert may be fixed by being fitted in a groove in the female screw component.

Abstract: In the packet scheduling device, the output class selection part is made to conduct the selective output of priority class, based on the weight count value calculated from a weight value corresponding to minimum guarantee bandwidth for each priority class and the amount of packet accumulated in each queue. The output class selection part operates so that if the weight count value is “0” or more, then the packet length of variable-length packet data to be output is subtracted from the current weight count value to give a renewed weight count value. On the other hand, if the weight count value is less than “0”, until reaching a predetermined repeat count (Cmax−1), the weight value of each priority class is added to the weight count value of all priority classes, and, when reaching the repeat count (Cmax−1), the weight value is added to the weight count value of all priority classes or replaced by half the weight value.

Abstract: A transfer destination determining apparatus and method performing a load distribution in a network, where a plurality of transfer destination subjects are present as a transfer destination of a datagram, while the same collected flows are transferred to the same transfer destinations, the transfer destinations are allocated with respect to each of the collected flows. This apparatus has an extracting part extracting address and flow discrimination information, in the IP datagram; route solving part determining a transfer path based on the address information. When the determined path is a single path, the transfer destination is uniquely determined and the path is outputted to a post-staged apparatus, whereas when the path is a multi-path having a plurality of transfer destination subjects a multi-path number is outputted to a flow managing means which determines a transfer path corresponding, to a collected flow based on the received flow discrimination information and the multi-path number.

Abstract: A lightwave network data communications system having such an architecture that routing operation within a lightwave network is simplified, and a high-speed transfer process is attained in a large-scale basic network utilizing a wavelength division multiplexing (WDM) technology which accommodates internet traffics from a plurality of subscriber networks.

Abstract: A network node of a SONET ring is provided with a tributary line interface that receives packets from LAN users. A packet switch performs a switching operation on the LAN packets. An aggregate line interface establishes an STM path on a communication link and a number of packet paths within the STM path. An STM switch connects the packet switch between the tributary line interface and the aggregate line interface so that the switched packets are transported over the packet paths. Monitoring circuitry monitors the LAN packets and produces a warning signal if an abnormal condition is detected in one of the packet paths and transmits the warning signal to the communication link. Preferably, the monitoring circuitry is provided in the tributary line interface.

Abstract: A loose source routing method is provided to transfer an IP packet from a transmission source gateway to a transfer destination gateway by way of ATM nodes, which are freely designated. At the transmission source gateway, the IP packet given from a user LAN is dissolved into ATM cells containing a BOM cell whose destination address designates the transfer destination gateway. In addition, at least one pseudo BOM cell whose destination address designates an ATM node in the ATM network is added and is located at a top place of a cell stream constructed by the dissolved ATM cells. Thus, the cell stream is transferred from the transmission source gateway to the designated ATM node in accordance with the destination address of the pseudo BOM cell. The designated ATM node discards the pseudo BOM cell so that the original BOM cell is now located at the top place of the cell stream.

Abstract: In an ATM connectionless communication system for delivering connectionless datagram in the form of sessions through an ATM network, each one of multiple edge units is connected to a user network where quality-of-service (QoS) sessions and No-QoS sessions are mixed. Each of the edge units accommodates an IPv4 packet from the user network into an intermediate frame and accommodates the intermediate frame into ATM cells. The edge units are connected to core units by permanent virtual paths to form a connectionless network. Each of the edge units has a session supervising section for determining whether the IPv4 packet is a QoS session or a No-QoS session, to allocate a control flow number to the IPv4 packet when the IP4 packet is a QoS session.

Abstract: A multi-layer class identifying communication apparatus, includes an input interface connected to input communication lines; a switch circuit; and an output interface connected to output communication lines. The input interface comprises an allocating section which determines a class identifier indicative of one of classes to which an IP packet belongs, from header data of the IP packet received through one of the input communication lines, and allocates an IP-QOS (Internet-Protocol-Quality-of-Service) code to the IP packet. The switch circuit selects one of the output communication lines based on a destination address of the IP packet, such that the IP packet is outputted from the output interface to the selected output communication output interface.

Abstract: The present invention provides a gateway unit which comprises a detecting unit for detecting the congestion from an RM cell from the ATM cell, for discriminating a TCP data gram (TCPDG) from a packet received during the congestion and for acquiring a sequence number of the TCPDG, a sending unit for sending an ACK having a window-controlled value to a transmitting terminal so as to limit a data transmission, and a discarding unit for discarding the packet from the transmitting terminal during the congestion after the confirmation of packet. During the congestion in the ATM network, a pseudo acknowledgment is sent from the gateway unit so as to indicate that the receiving terminal cannot receive data. This restrains the transmission of TCPDG from the transmitting terminal.

Abstract: In a high-speed routing control system, plural path candidates each leading to a destination node are selected on the basis of physical connection information of links connecting respective nodes in a path candidate selection unit 11, and a path candidate containing no congestion-occurring link is specified as the optimum path from the plural path candidates selected by the path candidate selection unit 11 in an optimizing unit 12. Accordingly, even when the destination node is nearer to the self node, the optimum path selection can be performed, and a switching operation to a bypass path can be performed at high speed. In addition, the traffic amount based on topology information can be suppressed, and the large-scaling of the network can be supported.

Abstract: In a connectionless communication system, a number of interworking units are provided for accommodating local area networks. At the internetworking units, a packet from the local area networks are segmented into cells for transmission to an ATM network. The cells contain a connectionless address designating a designation local area network, a virtual path identifier (VPI) designating a permanent virtual connection, and a virtual channel identifier (VCI) identifying the packet. The ATM network includes a number of cross-connect nodes interconnected by communication links. The cross-connect nodes establish a plurality of permanent virtual connections between the interworking units and the nodes and between the nodes in pairs, receive the cells from the interworking units and route the cells having VCIs of the same value through the permanent virtual connections to a destination interworking unit according to the connectionless address and the VPI contained in the cells.

Abstract: A video tape recorder enables a normal video signal for an aspect ratio of 4:3 or a wide-picture video signal for a greater aspect ratio of, for example, 16:9 to be selectively recorded/reproduced onto and from a magnetic tape. In order to identify which of the aspect ratios the reproduced video signal is based on, a recording mode signal indicative of the aspect ratio is recorded on the magnetic tape together with the video signal. A code signal or a pilot signal is used for the recording mode signal. In the reproducing operation, the aspect ratio of a reproduced picture is recognized from the recording mode signal, and a signal indicative of the aspect ratio is delivered to an external device, such as a television set, together with reproduced video/audio signals. In a case where the reproduced picture is a wide picture and where the external device does not conform to the wide picture, the aspect ratio of the video signal is changed.

Abstract: An apparatus and method for processing signals of an imaging device comprising a detection circuit for detecting the color temperature of a light source for illuminating an object of which the image is picked up and a circuit for varying .gamma. correction characteristics for chrominance signals, whereby the .gamma. correction characteristics are changed to reduce the gains for low level regions of input signals to .gamma. correction circuits in accordance with the color temperature, thereby enabling the final quantize noise to be reduced.

Abstract: In a digital signal processor for an imaging system, a first pixel signal including first and second color information items and a second pixel signal including third and fourth color information items are alternately outputted to generate an image signal, which is subdivided into a portion to be delayed by a horizontal scanning period and a portion not to be delayed such that these signals are thereafter combined to form an image signal having respective pixel signals so as to achieve a matrix processing on the resultant signal to attain red, blue, and green signals.

Abstract: This invention relates to a method and apparatus for processing a color video signal.